Where we can identify one person in immediate need, particularly where money is not the answer (drowning child etc) most people will act.

Where that one person is a beggar on the street, some people will act (give money), some won’t because of the danger of becoming entangled with a greater commitment than they want. (Just a couple quid more guv and I can…)

Where a group of people are in need through no fault of their own many people will give money but not commitment. Perhaps they are buying off their feelings of guilt for not being in that situation.

Where a person or group of people are perceived to have brought it on themselves, few people will act. They may even become angry at being asked to give when they are also in need.

To come back to the shoes…
Many people have assets worth more than their income but they are not easily used to help another when you still need to use them.

It appears to me that giving to charity is a moral and ethical minefield on a very personal level.